Truck will not move in any gear

[Brianolda]

Hello all. I'm looking for some help
Just got a 2001 GMC 3500 with the Allison with 111,000 miles. When driving it home a felt a small catch a few times. I thought it was probably a miss and didn't think much of it. When I was driving it in to the shop it caught again and sound kinda like a bringing sound for a split second. Got it in the shop changed all the fluids and went for a drive. Got about a mile down the road and it caught pretty good then roled to a stop. It would not go forward in any gear. Tried reverse and it went backwards for about 10' then stopped. If your in gear and give it a bit of gas you can here a buzzing sound. Any advice would be greatly appreciated.

 

[Mike L.]

Check transfer case.

 

[JoshH]

Does it have park?

 

[Brianolda]

While it's in park you can push it. I got it to pop a couple times while I pushed and the wife listened. She thought it was coming from the rear end around the rear wheels. I thought from the center of the truck. Thanks for help. I appreciate it.

 

[Brianolda]

I just tried it in 4wd. Nothing in high but would move in 4lo.

 

[JoshH]

Like Mike said, it sounds like a transfer case problem. Most likely a worn range shift fork.

 

[Brianolda]

Great. Thanks for the help. Going to get it pulled and tore apart. Is there any good tutorials on rebuilding the np263xhd?